Carburetor with adjustable fuel level control drains



Dec. 22, 1964 R. CAPEHART CARBURETOR WITH ADJUSTABLE FUE'IL. LEVEL CONTROL DRAINS 2 Sheets-Sheet 1 Filed July 8, 1963 MAN/FOLD INVENTOR. Aa/v/w: 2 (420/407 iffdiA i/i Dec. 22, 1964 L. R. CAPEHART 6 CARBURETOR WITH ADJUSTABLE FUEL LEVEL CONTROL DRAINS Filed July 8, 1963 2 Sheets-Sheet 2 INVENTOR. 4oAw/i 2 (295M497 United States Patent 3,162,235 CARBURETUR WITH ADJUSTABLE FUEL LEVEL C(DN'IROL BRAINS Lonnie Robert Capehart, Uhiah, Qalif, assignor to The Capehart-Zhitnofi Corporation, Ukiali, Calif, a corporation of (Jalife-rnia Filed July 8, 1963, Ser. No. 293,438 3 Claims. (Cl. 15836.3)

This invention relates generally to fuel level controllers for carburetors and the like of the type wherein outlet drains are provided in the float-bowl of the carburetor at the normal fuel level thereof to drain excess fuel caused by deviation of the fuel level from a horizontal position, and is particularly directed to an adjustable drain fitting which is readily adjustable to drain from a desired fuel level of the carburetor bowl whether or not the fitting is installed precisely at the normal fuel level of the bowl.

Various fuel level controllers are well known for employment with carburetors and the like to prevent flooding which occurs as a result of displacement of the fuel in the carburetor bowl, or float chamber, from its normal horizontal level. This may occur, for example, when sudden acceleration or deceleration of the automobile causes the normally horizontal level of fuel in the carburetor bowl to assume a cant. Various existing fuel level controllers obviate the problem by providing overflow orifices about the periphery of the carburetor bowl at the normal horizontal fuel level thereof, which, consequently, act to drain off the temporary excesses of fuel which occur when the level at an orifice is exceeded due to the fuel deviating from its normal horizontal level. My prior U.S. Patents, Nos. 2,998,056 and 3,086,580, disclose fuel level controllers of this type, wherein overflow fittings are installed about the periphery of a carburetor bowl at the normal fuel level thereof. These fittings are connected to an overflow tank, which collects the excess fuel from the bowl flowing through the overflow fittings when the fuel level thereat rises above the level of the bowl at which they are installed. In order that the overflow fuel be efficiently utilized, provision is made to recirculate same from the overflow tank to the carburetor. In this regard, the above-referenced patented controllers generally include valve means for diverting the supply of fuel to the fuel pump, from the storage tank to the overflow tank in response to an auxiliary float within the overflow tank rising to a predetermined level.

It Will be appreciated that in order for fuel level controllers of the foregoing type to be effective, the overflow orifices must be rather precisely positioned at the normal fuel level of the carburetor bowl. Heretofore, the overflow fittings have been installed substantially exactly at the normal fuel level of the bowl. This has entailed very careful measurement and drilling in order to provide apertures for properly positioning the fittings at the overflow point, or fuel level, of the carburetor. More particularly, where a normal fuel level is known, drilling and tapping tolerances of of an inch are required in providing the apertures to insure proper functioning of the fittings received therein; and this has proven to be very difficult and time consuming to the average mechanic. Moreover, the exact fuel level of some makes and models of carburetors are not available from the manufacturer and must be determined on an experimental trial-and-error basis. In many instances, where the overflow fittings are installed with precision at what is apparently the proper fuel level of the carburetor, operational checks have shown improper fitting placement due to the actual fuel level deviating from that given as the normal level of, the carburetor. In these instances, plugging of the holes and $162,235 Patented Dec. 22, 1964 reinstalling of the drain fittings are, accordingly, usually necessary, or under some circumstances the situation may require adjustment of the float.

The present invention overcomes the foregoing disadvantages and limitations encountered in the installation of overflow fittings of fuel level controllers in a carburetor, by providing an adjustabie drain fitting which does not require exacting measurements in its installation, but rather may be simply adjusted to the normal level of fuel in the carburetor bowl. More explicitly, the fitting includes a head which is adapted for attachment to the bowl of a carburetor at a position below the normal fuel level thereof. The head has an axial inlet passage in open communication with the fuel below the normal level thereof when the head is thus installed. The fitting further includes a vented pipe, or other means defining a passage, extending from the inlet passage in angular relation thereto. Provision is made for rotation of this second passage relative to the axis of the inlet passage. For example, the head may be adapted for threadable engagement with the bowl while the pipe, or other means, defining the second passage is in fixed securance with the head. Thus, in the threaded engagement of the head with the bowl, the over-all fitting including the second passage is rotatable with respect to the axis of the inlet passage. The fitting further includes an outlet in communication with the second passage at a point displaced from the inlet passage. In use, fuel enters the inlet passage from the bowl and extends into the second passage. In the circumstance that the second passage extends upwardly from the inlet passage, the fuel assumes a level in the second passage in horizontal alignment with the actual level of fuel in the bowl, any siphoning action being prevented by the venting of the second pasage. The fitting is then unitarily rotated, or the second passage otherwise rotated with respect to the axis of the inlet passage, until fuel just begins to drip from the outlet. At this time the highest point of the outlet, commonly its point of intersection with the second passage, is in horizontal alignment with the actual level of fuel in the carburetor bowl. It will be thus appreciated that the high point of the outlet is readily precisely adjustable to the actual level of fuel in the bowl, and such high point constitutes the overflow point thereof. Accordingly, when the normal level of fuel in the bowl is exceeded, fuel flows from the outlet just as if the outlet were installed directly upon the bowl precisely at the normal fuel level thereof.

The invention is hereinafter more fully described, and illustrated in the drawing with respect to a single preferred embodiment of the overflow drain fitting as employed in a fuel level controller for preventing flooding of a car buretor. In the drawing:

FIGURE 1 is a schematic diagram of a carburetor fuel level controller in which adjustable drain fittings, in accordance with the present invention, are employed;

FIGURE 2 is a plan view of the drain fitting;

FIGURE 3 is a sectional view taken at line 3-3 of FIGURE 2;

FIGURE 4 is an elevational view, with portions broken away, of the drain fitting as installed on a carburetor bowl prior to adjustment of the fitting to the level of fuel in the bowl; and

FIGURE 5 is a view similar to FIGURE 4, but with the fitting adjusted to the fuel level of the bowl.

Referring now to FIGURE 1, there will be seen to be provided a fuel level controller of the general type disclosed in my prior patents, Nos. 2,998,056 and 3.086580, arranged to prevent flooding of a float-type carburetor, which includes a float chamber or bowl 1].. Such a carburetor includes a float I2 immersed in fuel 13 within the bowl and operable to control the rate at which fuel is metered into the bowl through a needle valve 14, in ac-' intake manifold 13, where the fuel is vaporized, combined. 7 with air, and metered to the combustion chambers of the engine. I

The fuel level controller, which operates to prevent flooding which would normally arise whenthe level of fuel in the bowl assumes a non-horizontal position, includes a plurality of overflow outlets 19, provided about the periphery of the bowl in a horizontal plane atsubstantially the height of the normal level of fuel therein. Under normal conditions where the fuel'level in the bowl is horizontal, fuel does not flow into the overflow orifices 19 and, hence, the normal fuel level is maintained. When the fuel level departs from the horizontal due to a sudden acceleration, deceleration or the'like, the fuel level at one or more of the overflow outlets 19 will exceed the vertical height thereof and, hence, the temporary excess of fuel thereat will drain into the outlets and reduce the level of the fuel within the bowl. This reduction in fuel level compensates for additional fuel flowing into the bowl due to temporary malfunction of the float 12 and prevents flooding in order that the overflow fuel may be re-cycled to the bowl l1 and, hence, efliciently utilized, pipes 21 from the overflow outlets 19 are commonly connected, as by means of a union 22, to the inlet 23 of an overflow tank 24. The overflow fuel is-collected in the tank 24 and provision is made to deliver fuel therefrom to the fuel pump 16 when a predetermined level of fuel is collected in the tank 24. At times, the fuel pump 16 is pumping fuel from the overflow tank 24, it is, of course, desirable that the flow of fuel from the storage tank 17 be simultaneously terminated. To this end, the controller includes valve means 26 having an inlet communicably connected to the overflow tank 24, a second inlet communicated with the fuel storage tank 17, and an outlet connected to the fuel pump 16. The valve means further include a float '27 disposed within the overflow tank 24 and-buoyed by the fuel collectedtherein which is operable to switch communication through the valve means to the outlet, from apertures in'the carburetor bowl at positions wherein the lowest points of the apertures are substantially precisely at the normal level of fuel in the bowl. This, of course, requires very exacting measurement and precision .in drilling and tapping, and furthermore requires the prior determination of the normal fuel level within close tolerances.

The present invention manifestly improves the abovenoted situation by providing an overflow or drain fitting 28 which affords adjustability of the overflow level of its outlet to preciselythe normal horizontal fuel level prevailing in a carburetor bowl, such as the bowl 11. By virtue of its adjustability, the fitting 28 facilitates positioning of its overflow level to the normal fuel level in the bowl without precise positioning of an aperture in the bowl for receiving the fitting. More particularly, the drain fitting 28 in its broader aspects includes a head or the like which is adapted to be received within an aperture in the carburetor bowl which is'below the normal level of fuel therein. An .inlet'passage is provided coaxially of the head for free communication with the fuel in thebowl and means arerprovided to definea second passage which extends from the head passage in angular relation thereto and which is'vented to atmosphere. An outlet is provided in communication with the secondpassage at' a point thereof which is displaced from the inlet passage. In addition, provision is made for rotation of :the second passage'with respectto the axis'of the inlet passage. For

example, the second passagemay be provided in fixed relation to the inlet passage and't-he head adapted for threaded, or other rotary engagement in the bowl aperturef When the head is rotated in the aperture, the entire fitting is'hence. rotated about the head axis and the second passage is thereby rotated with respect to the axis one inlet to the other depending upon the level of fuel in the overflow tank. More particularly, the valve means 26 is arranged such that the second inlet and the outlet are normally communicated and the fuel pump 16 pumps fuel fromthe storage tank 17 to the float-bowl 11 in the usual manner. However, when the float 27 assumes a predetermined level within the overflow tank 24, communication is responsively hifted from between the second inlet and the outlet, to between't'he first inlet'and the outlet, whereby the fuel pump 16 now pumps. fuelfrom the overflowtank 24 to the float-bowl 11. For further details of the operation of fuel level controllers of the type outlined above, reference is made to my prior patents, Nos. 2,998,056 and 3,086,580.

As noted previously, in level controllers of the foregoing type, the overflow outlets 13 must be positioned with substantial precision in order to insure proper operation of the level controller. More particularly, the outlets must be positioned such that no fuel flows therefrom when the fuel within the bowl 11 isat its normal horizontal level; and yet, fuel must flow from the outlets upon even the slightest departure of the fuel from the normal hori zontal level. Heretofore, conventional fittings have been employed as the overflow outlets l9, and this has entailed installation of the fittings upon the bowl at very precise positions. Conventional fittings afford no adjustability and, accordingly, their installation involves drilling of ni'cation with the passage 32.

of the inlet passage. By:virtue of theangular orientation of the second passage with respect to the inlet passage, the second passage togetherwith its outlet are adjustable through a range of vertical positions relative to the bowl upon rotation of the second passage with respect to the axis of the inlet passage. Accordingly, the second passage may be rotated to a position wherein its intersection with the outlet, or other uppermost point of the outlet, is exactly horizontally level with the normal fuel level of'the bowl. Such uppermost point of the outlet'represents the discharge level of the fitting and same is thus precisely positioned at the normal fuel level of the bowl. border that the fitting maybe secured in this position, same further in- 'cludes fastener means for selectivelyj rigidly fixing the rotary position of the second passage relative to the axis of the inletpassage.

The adjustable overflow fitting 28 will be better understood upon consideration of the preferred structural embodiment thereof illustrated in FIGURES 2-4. As noted above, the fitting includes ahead, which is preferably provided as a hexagonal boss 29, including an externally threaded nipple 31 and a'coaxial passage 32 extending thereinto to thus define the inlet passage for free communication with fuel in the carburetor bowl 11; The periphery of the nipple is preferably faced as indicated at 33 to provide a planar surface which i inclined'with respect to the nipple axis andhence with respect to the passage 32. A tapped bore 34 extends-into the inclined face 33 in normal relation thereto and angularly intersects the inlet passage 32. The tapped bore provides for the attachment or, a pipe 36 to the nipple in angular commu- Itwill be appreciated that numerous alternatives are possible in the communicable attachment of a pipe to the nipple, for example, the pipe ticularly, the pipe bore and first passage of the coupling define a passage 38 which extends from the inlet passage angularly intersects passage 38 in preferably right angular relation, while the third passage of the coupling is advantageously defined by a tapped bore 41 which intersects the passage 38 at an angle of preferably 135 thereto, as well as to the bore 39. A pipe 42 having an externally threaded end 43 engaged within the tapped bore 41 and closed at its opposite end as indicated at 44, has a bore 46 in communication with the passage 38 and thereby forms an extension thereof. The pipe 42 is provided with vent apertures 47 adjacent its closed end 44 and thus the passage 38 and bore 46 define the second passage of previous mention which is vented to atmosphere, in the present instance at the opposite end of the passage from its intersection with the inlet passage 32. An outlet cock 48 is threadably engaged within the tapped bore 39, such that its bore 50 communicates with the passage 38 and thus intersects the over-all passage defined by passage 38 and the bore 46 of pipe 42 at an intermediate position as indicated at 51. This intersection 51 of the instant embodiment defines the uppermost point of the outlet of previous mention which may be adjustably positioned on a horizontal level with the normal fuel level prevailing in the carburetor float-bowl 11. However, various alternative structural arrangements are, of course, possible where the outlet initially extends upwardly from its intersection with the passage and the uppermost point of the outlet is thus different from the passage intersection 51. Also, it will be appreciated that various alternatives are possible in the securance of the pipe 42 and outlet cock 48 to the coupling 37, and that the passages defined by the bores of these elements may be provided by various alternative structures.

With a tapped aperture provided in the bowl 11 at a position beneath the normal fuel level thereof, which aperture may be positioned, drilled and tapped with relative imprecision, the threaded nipple portion 31 of the outlet fitting 28 is engaged within the tapped aperture. When the fitting is rotated to a position, as depicted in FIGURE 4, it is to be noted that the fuel enters the inlet passage 32 and extends into passage 38 to a position short of the intersection 51 of the outlet cock bore 50 with the passage. More particularly, the fuel in the passage 38 assumes a horizontal level equal to that of the fuel within the bowl, the vents 47 preventing any siphoning action by equalizing the pressures acting within the passage and within the bowl, respectively. In FIGURE 4, no fuel drips from the outlet cock 48 inasmuch as its uppermost point, i.e., its intersection 51 with the passage 38, is at a higher level than the normal fuel level within the bowl. Now, when the fitting is rotated in the direction of the arrow until fuel begins to drip from the outlet cock 48, as depicted in FIGURE 5, the level of the intersection point 51 is hence on a horizontal level with the fuel level within the bowl. In other words, when the fitting is positioned as indicated in FIGURE 5, it is equivalent to a conventional fitting being engaged within an aperture precisely positioned in the bowl at the normal horizontal fuel level therein. With the fitting 28 thus properly positioned, to provide an overflow outlet at substantially precisely the normal fuel level of the bowl, the fitting may be locked in position upon tightening a speed nut 52, or equivalent fastener, carried upon the threaded nipple portion 31 against the wall of the bowl. With a plurality of the adjustable drain fittings 28 thus secured about the periphery of the bowl 11 and adjusted to the normal fuel level thereof, the pipes 21 are secured to the outlet cocks 48 of the respective fittings, to thus connect the level controller to the carburetor bowl in proper operative relation thereto.

While the present invention has been described hereinbefore in detail with respect to a single preferred embodiment, it will be appreciated that numerous variations and modifications may be made therein without departing from the spirit and scope of the invention. For example,

'cates with this recess.

rotation of the second passage relative to the axis of the head or inlet passage may be facilitated by various structural alternatives to the specific arrangement of the preferred embodiment. In this regard, one possible alternative comprises the attachment of the pipe defining the second passage to acup rotatably mounted in selectively fixed position upon a tubular head fixedly secured to the bowl. The cup may include a recess in aligned communication with the head bore, and the pipe bore communi- Thus, rotation of the second passage relative to the head passage is provided by rotation of the cup upon the head rather than by rotation of the over-all fitting. Therefore, it is not intended to limit the invention except by the terms of the appended claims.

What is claimed is:

1. In .a carburetor fuel level controller of a type which includes an overflow tank provided with an inlet for connection to a carburetor float-bowl at the normal fuel level thereof, and float actuated valve means having an inlet communicated with the overflow tank, a second inlet communicated with a fuel storage tank, an outlet communicated with a fuel pump in turn connected to the float chamber to pump fuel thereinto, and an actuating float disposed in the overflow tank for switching communication from between the second inlet and outlet of the valve means to between the first inlet and outlet thereof in response to a predetermined fuel level in the overflow tank, the improvement comprising adjustable drain fittings, each including a head for securance to a carburetor float-bowl below the normal fuel level thereof and having an axial inlet passage for communicating with the interior of said bowl, means defining a second passage extending from said head in angular relation to said inlet passage and communicating therewith, means venting said second passage to atmosphere, means providing for selective rotation of said second passage with respect to the axis of said inlet passage, means defining an outlet communicating with said second passage at a point displaced from said inlet passage, and fastener means for selectively rigidly fixing the rotational position of said second passage relative to the axis of said inlet passage; and means communicably connecting said outlets of said drain fittings to the inlet of said overflow tank.

2. In a carburetor fuel level controller of a type which includes an overflow tank provided with an inlet for connection to a carburetor float chamber at the fuel level thereof, and float actuated valve means having an inlet communicated with the overflow tank, a second inlet communicated with a fuel storage tank, an outlet communicated with a fuel pump in turn connected to the float chamber to pump fuel thereinto, and an actuat-ing float disposed in the overflow tank for switching communication from between the second inlet and outlet of the valve means to between the first inlet and outlet thereof in response to a predetermined fuel level in the overflow tank, the improvement comprising adjustable drain fittings, each including a nipple for threadably engaging the float chamber of a carbuertor below the normal fuel level thereof, said nipple having an axial passage therein for communication with the interior of said chamber, means defining a second passage extending from the end of the first passage in said nipple in angular relation thereto and vented to atmosphere at its opposite end, means defining an outlet communicating with said second passage at an intermediate point thereof, and fastener means engaging said nipple for locking same at a rotary position of it's engagement with said float chamber at which the point of communication between said second passage and the outlet therefrom is at the normal fuel level of said float chamber; said outlets of said drain fitting communicably connected to the inlet of said overflow tank.

3. In a carburetor fuel level controller of a type which includes an overflow tank provided with an inlet for inlet communicated with the overflow tank, a second inlet communicated witha fuel storage tank, an outlet communicated with a fuel pump in turn connected to 7 ,4 connection to a carburetor float-bowl at the normal fuel a level thereof, and float actuated valve means having an stantially 135 aangular relation thereto, said coupling secured to said pipe .with said first passage in aligned communicationtherewith, an outlet cock secured to said the float-bowl to pump fuel thereinto, and an auxiliary float disposed in the overflow tankffor switching-communication from between the second inlet and outlet drain fittings, each including a threaded nipple having an axial inlet passage extending thereinto for threadably engaging the float-bowl of the carburetor below the fuel level thereof, a pipe extending vfrom said nipple in angular relation to .a transverse plane through said passage and communicating therewith, a Y coupling having first and second substantially right iangu-larly intersecting passages and a third passage extending from the intersection of said first and second passage in subcoupling in aligned communication with said second passage, ;.a vent pipe secured w said coupling in aligned CCmInllDlC'atlOH 'Wlth said third passage, and fastener means engaging the threaded .portion of said nipple for locking-same at a rotary position; of 'its'. engagement with said float-bowl, at which-the point of communication between said first and second passages of said coupling is horizontally aligned with said normal fuel level of said float-fbowL 'said outlet .cocks of said drain fittings communicably connected to the inlet of said overflow tank.

t References Cited in thefile of this patent UNITED STATES PATENTS 'Capehart Apr. 23, 

1. IN A CARBURETOR FUEL LEVEL CONTROLLER OF A TYPE WHICH INCLUDES AN OVERFLOW TANK PROVIDED WITH AN INLET FOR CONNECTION TO A CARBURETOR FLOAT-BOWL AT THE NORMAL FUEL LEVEL THEREOF, AND FLOAT ACTUATED VALVE MEANS HAVING AN INLET COMMUNICATED WITH THE OVERFLOW TANK, A SECOND INLET COMMUNICATED WITH A FUEL STORAGE TANK, AN OUTLET COMMUNICATED WITH A FUEL PUMP IN TURN CONNECTED TO THE FLOAT CHAMBER TO PUMP FUEL THEREINTO, AND AN ACTUATING FLOAT DISPOSED IN THE OVERFLOW TANK FOR SWITCHING COMMUNICATION FROM BETWEEN THE SECOND INLET AND OUTLET OF THE VALVE MEANS TO BETWEEN THE FIRST INLET AND OUTLET THEREOF IN RESPONSE TO A PREDETERMINED FUEL LEVEL IN THE OVERFLOW TANK, THE IMPROVEMENT COMPRISING ADJUSTABLE DRAIN FITTINGS, EACH INCLUDING A HEAD FOR SECURANCE TO A CARBURETOR FLOAT-BOWL BELOW THE NORMAL FUEL LEVEL THEREOF AND HAVING AN AXIAL INLET PASSAGE FOR COMMUNICATING WITH THE INTERIOR OF SAID BOWL, MEANS DEFINING A SECOND PASSAGE EXTENDING FROM SAID HEAD IN ANGULAR RELATION TO SAID INLET PASSAGE AND COMMUNICATING THEREWITH, MEANS VENTING SAID SECOND PASSAGE TO ATMOSPHERE, MEANS PROVIDING FOR SELECTIVE ROTATION OF SAID SECOND PASSAGE WITH RESPECT TO THE AXIS OF SAID INLET PASSAGE, MEANS DEFINING AN OUTLET COMMUNICATING WITH SAID SECOND PASSAGE AT A POINT DISPLACED FROM SAID INLET PASSAGE, AND FASTENER MEANS FOR SELECTIVELY RIGIDLY FIXING THE ROTATIONAL POSITION OF SAID SECOND PASSAGE RELATIVE TO THE AXIS OF SAID INLET PASSAGE; AND MEANS COMMUNICABLY CONNECTING SAID OUTLETS OF SAID DRAIN FITTINGS TO THE INLET OF SAID OVERFLOW TANK. 